Recently, with progress of the technology and high development of the culture, development of everything is toward user friendly and convenient direction. However for the blind, complete blind-guide facilities will contribute largely to convenience of the blind's action. The method for helping the blind to act without obstacles is not beyond the scope of warning the blind by blind-guide facilities, for example, providing warning voice at traffic lights or in the elevator, or setting up blind-guide bricks on the sidewalk. However, all these blind-guide facilities are not enough and cause inconvenience for the blind. Other methods such as eye cornea surgery and setting up electronic eyes to help the blind rebuild the vision are expensive, and for the present technology, electronic eyes can only let the blind see light-spots and simple geometric figures. Therefore, auxiliary tools of blind-guide become indispensable tools for leading the blind.
Auxiliary tools use various principles. For example, Taiwan Patent No. 324163 discloses a blind-guide walking stick whose principle is similar to the principle of detecting obstacles when bats fly. First, the blind-guide walking stick emits ultrasonic waves, and the ultrasonic waves are reflected by obstacles to form reflection waves. The bat senses the time interval between emitting and receiving the ultrasonic waves to estimate the distance between the obstacles and the bat itself, and the blind-guide walking stick can estimate the distance between the object and the blind user. Finally, the blind user is notified of the distance in voice.
Taiwan Patent Application No. 095127251 discloses an electronic blind-guide device, which uses GPS collocated with the electronic map to tell the blind where he is in voice. Besides, the mentioned electronic blind-guide device can also detect the obstacles around the blind and send out warning, and has the function of recording the environmental image.
However, the method of detecting obstacles in the prior art is not accurate enough. In order to overcome the drawbacks in the prior art, an optical blind-guide apparatus and the method thereof are provided. The particular design in the present invention not only solves the problems described above, but also is easy to be implemented. Thus, the present invention has the utility for the industry.